This invention relates to cerburetors for internal combustion engines, and more particularly to an improvement in a carburetor for use in a motor vehicle.
With the strengthening of measures taken in recent years for preventing enviromental distruption by noxious effluents released to atmosphere, there have been increasingly severe restrictions imposed by law on the amounts of noxious components of exhaust gases of motor vehicles. The cope with this situation, prescription has been designed in formulating requirements to be satisfied by internal combustion engines, particularly for use in motor vehicles, for the purpose of eliminating the problem of air pollution by the exhaust gases of motor vehicles. However, a difficulty has been experienced in meeting the conflicting demands to reduce air-polluting constituents of exhaust gases on one hand and to improve the performance of a motor vehicles and decrease the fuel consumption thereof on the other. As a means for satisfying these conditions, carburetors which have a great deal to do with the combustion of fuel in the engines have come to attract the attention of those concerned in the motor vehicle industry. More specifically research has in recent years been conducted in various countries on carburetors for effecting incresed vaporization of fuel and stabilization of a flow of mixture of atomized fuel particles and air from the carburetor to the engine.
Of all the types of carburetors now in use, a carburetor which have been most favored are of the type which uses what is referred to as an air fuel mixing tube which is a metal tube formed therein with many apertures and arranged in the fuel passage at a level lower than the fuel level in the fuel passage for ejecting air through the apertures in order to convert fuel into atomized particles. Various programs have been under way to conduct studies on the number and position of the air ejecting apertures so as to provide improvements in this type of carburetors. However, a flow of fuel to the engine still tends to become an intermittent flow at the time the engine is started or abruptly accelerated and the fuel begins to gush out, and the particles of fuel are still large in size. As a result, the air-polluting constituents of exhaust gases are still large in amounts.